Biofuel

fu·el [noun] plural noun: fuels 1. material such as coal, gas, or oil that is burned to produce heat or power. synonyms:gas, gasoline, diesel, petroleum, propane; power source; petrolgasgasolinediesel petroleumpropanepetrol

bi·o·fu·el [noun] plural noun: biofuels 1. a fuel derived directly from living matter.

bi·o·eth·a·nol [noun] noun: bioethanol; noun: bio-ethanol 1. ethanol produced from plants such as sugar cane or corn, used as an alternative to gasoline. ethanol bioethanol

bi·o·die·sel [noun] noun: biodiesel; noun: bio-diesel 1. a biofuel intended as a substitute for diesel. gas·o·line [noun]: gasoline; noun: gasolene 1. refined petroleum used as fuel for internal combustion engines.

Feedstock CO 2

Biomass –Plants –Animals (by way of plants) Plants –Use solar energy to convert water and CO 2 to sugars through the process of photosynthesis –Harvested portions of live plants or remains are sources of biomass Animals –Consume plants (or consumers of plants) –Elimination products or remains are sources of biomass Virtually all of our current energy supply is derived from biomass (fossil fuels are just “well-aged”)

Multiple Feedstocks treestrees grassgrass agricultural residuesagricultural residues energy cropsenergy crops municipal solid waste municipal solid waste sewage sludge sewage sludge animal manure animal manure

U.S. Biodegradable Wastes Municipal Solid Waste Sewage Sludge Industrial Biosludge Recycled Paper Fines Agricultural Residues Forestry Residues Manure Amount (million tonne/year) Alcohol Potential Waste (billion gal/year) Total 1, U.S. Gasoline Consumption = 130 billion gal/year U.S. Diesel Consumption = 40 billion gal/year

How to Get Liquid Transportation Fuels from Biomass Convert sugars and starches to ethanol – fermentation Convert plant oils to biodiesel – transesterification Convert anything to liquid – pyrolysis Convert anything to gas (gasification) with subsequent conversion to liquid – aka biomass to liquids (BTL)

The Challenge Jet Fuelforestwastecornstover switch-grass Gasification to “syngas” (CO + H 2 ) Diesel Gasoline Lignocellulose Fisher-Tropsch methanol Gasoline corngrain sugarcane starch Saccharification ligninburn Enzymatic Fermentation Ethanol Pyrolysis, fast or slow gases bio-oil sugar Sugar/starch Liquid Phase Processing Dissolution Can we achieve sufficiently high yields of targeted chemical compounds from solubilized biomass fractions to justify the cost of biomass pretreatment?

Biofuels, in Order of Maturity, p1 of 2 Adopted from NREL (2006) FUELSOURCEBENEFITSSTATUS Grain/Sugar Ethanol Corn, sorghum, sugarcane High-octane Widely available sources Commercially proven BiodieselVegetable and seed oils; fats and greases Increased fuel lubricity Widely available sources Commercially proven Gasoline and diesel blends Ethanol or biodiesel blended with petroleum fuels Relatively straightforward for refineries to process Decreased sulfur emissions over standard fuels Commercial trials in progress Cellulosic Ethanol Grasses, wood chips, and agricultural residues High-octane Less demand on agricultural lands than grain ethanol DOE program targeting 2012 demonstration ButanolCorn, sorghum, wheat, sugarcane Low-volatility High energy-density Water tolerant BP and DuPont in progress

Biofuels, in Order of Maturity, p2 of 2 FUELSOURCEBENEFITSSTATUS Pyrolysis Liquids Lignocellulosic biomass Can utilize waste products Potential source of aromatics and phenols Several commercial facilities produce energy and chemicals Syngas Liquids Various biomasses Can utilize waste products Can be integrated with fossil fuel sources (e.g., coal) High quality fuel Commercially demonstrated a large scale using fossil fuels; biomass projects underway Biodiesel or jet fuel MicroalgaeHigh yield per acre Could be integrated with CO 2 capture and reuse Demonstrated at pilot scale in 1990s. Many start-ups currently underway Hydrocarbons (designer fuels) Biomass carbohydrates Generate synthetic copies of current petroleum derived feedstocks Laboratory-scale research Adopted from NREL (2006)

Ethanol (EtOH) Chemical Composition –CH 3 CH 2 OH or (C 2 H 6 O) –Ethanol is ethanol – source independent Also known as ethyl alcohol or grain alcohol 2 types: –Biologic: conversion of starches to sugar followed by fermentation of sugar with yeast –Synthetic: acid catalyzed hydration of ethylene Blending –Currently used as a additive (10% max) to improve performance (octane) of gasoline –Internal combustion engines must be designed to accommodate ethanol content >10% OH

Ethanol Sources Most common sources are plants with high sugar or starch content (e.g., corn, beets, cane, potatoes) Sources with more complex cellular structures (e.g., wood, grass, stalks) require more effort to extract available sugars (cellulosic ethanol)

Biodiesel or FAME (Fatty Acid Methyl Ester) Chemical composition –Similar to petroleum diesel fuel in structure (straight chain) and number of carbon atoms (10 to 20) –Differs in that it is oxygenated and has a small number of double bonds –Fuel characteristics will vary slightly depending upon source Blending –Completely miscible with diesel fuel –Used as an additive (5% max) to increase cetane and improve performance of diesel –Internal combustion engines must be designed to accommodate fuels with FAME content >5%

Biodiesel Sources Plant oils –Soybean –Palm –Rice –Cottonseed –Rapeseed (canola) Waste oils (plant and animal) Algae – recent interest because –High amounts of oil –Minimal competition with food crops and crop land –Can be grown on land with low potential for CO 2 sequestration (e.g. deserts) –Does not necessarily require fresh water

BIODIESEL – Final Product Biodiesel 100% Glycerin

Biomass to Liquids (BTL) via Gasification Solid or solid/liquid biomass is converted to gas at high temperatures in the presence of small amounts of oxygen Main objective is to transfer the maximum amount of chemical energy within the feedstock to the gaseous fraction by producing a high yield of low molecular weight products (high H:C) The resulting gas is “conditioned” to produce synthesis gas (syngas) Syngas is then converted to liquid fuel via the Fischer-Tropsch process

High-Productivity Feedstocks Corn grain Sweet sorghum Energy cane Productivity Dry tons/(acre·yr)

Sweet Sorghum Grows in ~35 US states

Energy Cane

High Agricultural Income Corn grain Sweet sorghum Energy cane ($2.40/bu) ($40/tonne) ($40/tonne) Gross Income $/(acre·yr)